This invention relates to the assembly and mechanical retention of an electromagnetic fuel injector on a fuel rail cup.
It is known to use spring metal clips for the mechanical retention of an electromagnetic fuel injector on a fuel rail cup.
Examples are shown in U.S. Pat. No(s). 4,474,160; 4,475,516; and 4,539,961. The spring retention clip which will be illustrated and described in the ensuing description of a preferred embodiment has heretofore been used for mechanical retention of a fuel injector on a fuel rail cup, and hence the clip, per se, is not novel.
Certain internal combustion engines have two intake valves per cylinder, and when a fuel injection system is used in such engines, it is usually desirable to employ an injector of the split-stream type for each cylinder. Such an injector splits the injected fuel stream into one portion directed toward one valve and another portion directed toward the other valve. In order for the split streams to be properly aimed, it is necessary for the injector to be properly circumferentially located in the fuel rail cup. It is also desirable to make the assembly of the injector to the cup inherently properly circumferentially located in the injector.
In one prior construction for circumferentially locating the injector in the cup, an additional block was added to the rail. This block had flats machined into it, and retention clips were redesigned for coaction with the block in locating the injectors. The wiring harness to the injectors also had to be made into a bus bar orienting the injectors. This prior construction increased the number of parts involved in a given engine system and it required certain redesign of the clip.
The present invention relates to a construction which retains the use of the illustrated retention clip, and adds essentially no cost to the manufacture of either the injector or the cup. The invention involves the creation of a key in the heretofore purely circular lip of the cup. This key has a coaction with the clip causing the injector to be properly circumferentially located at assembly to the cup. The material used to form the key would otherwise be part of the offal stock that is trimmed from the perimeter of the blank after the cup has been drawn. Accordingly, the material of the key is free, and the only modification required to the prior fabrication of the cup is to change the shape of the trim die so that the key is included in the cup's lip. Thus, the invention enables circumferential location of the injector to the cup to be obtained without having to modify the current injector or the current retention clip, thereby saving on the costs that would otherwise be involved with the prior approach described above.
Further features, advantages, and benefits of the invention will also appear in the detailed description of a preferred embodiment of the invention. Drawings accompany this disclosure and represent the best mode contemplated at this time for carrying out the invention.